Ghivari Sheetal B, Kubasad Girish C, Deshpande Preethi
Department of Conservative Dentistry and Endodontics, Sharad Pawar Dental College, Sawangi (Meghe), Wardha, Maharashtra, India.
J Conserv Dent. 2012 Jan;15(1):32-5. doi: 10.4103/0972-0707.92603.
To evaluate the bacteria extruded apically during root canal preparation using two hand and rotary instrumentation techniques.
Eighty freshly extracted mandibular premolars were mounted in bacteria collection apparatus. Root canals were contaminated with the pure culture of Enterococcus fecalis (ATCC 29212) and dried at 37°C for 24 h. Bacteria extruded were collected, incubated in brain heart infusion agar for 24 h at 36°C and the colony forming units (CFU) were counted.
The mean number of colony forming units were calculated by One-way ANOVA and comparison between the groups made by multiple comparison (Dunnet D) test.
The step-back technique extruded highest number of bacteria in comparison to other hand and rotary Ni-Ti systems.
Under the limitation of this study all hand and rotary instrumentation techniques extruded bacteria. Among all the instrumentation techniques step-back technique extruded more number of bacteria and K-3 system the least. Further in vivo research in this direction could provide more insight into the biologic factors associated and focus on bacterial species that essentially play a major role in post instrumentation flare-ups.
使用两种手动和旋转器械预备技术，评估根管预备期间根尖挤出的细菌。
将80颗新鲜拔除的下颌前磨牙安装在细菌收集装置中。根管用粪肠球菌（ATCC 29212）纯培养物污染，并在37°C下干燥24小时。收集挤出的细菌，在脑心浸液琼脂中于36°C孵育24小时，并计数菌落形成单位（CFU）。
通过单因素方差分析计算菌落形成单位的平均数，并通过多重比较（Dunnet D）检验进行组间比较。
与其他手动和旋转镍钛系统相比，逐步后退技术挤出的细菌数量最多。
在本研究的局限性下，所有手动和旋转器械预备技术都会挤出细菌。在所有器械预备技术中，逐步后退技术挤出的细菌数量更多，而K-3系统挤出的细菌数量最少。进一步在这个方向上的体内研究可以更深入地了解相关的生物学因素，并关注在器械预备后炎症发作中起主要作用的细菌种类。
